As planes roared towards take-off on the other side of the busy dual carriageway, a trumpet and whistle played nursery rhyme Incy Wincy Spider for protesters arriving at BAA headquarters at Heathrow Airport.

Many protesters dressed up as clowns for the occasion

The protesters, most in wet weather gear and many wearing clown wigs, began setting up mobile pop-up tents in the BAA car park under the watchful eye of police in riot helmets bearing plastic shields.

To minimise disruption to the handful of BAA staff at work on a Sunday, the police tried to contain the protesters in the corner of the car park.

When activists made up their own minds about where to take up positions, police shields were used to push them back.

Each handful of protesters arriving on the scene was greeted with claps and cheers.

Where many had been part of the climate camp at Heathrow throughout the week, others arriving at BAA came just for the day.

I feel that middle-class professional people have to make a stand because we are among the worst culprits